My datastructure only contains the last subjects information. So in my for loop the structure is getting overwritten. How can I change this?

Data= struct(); %Defines Datastructure
Subjects = dir('C:\Users\kaatg\OneDrive\Documenten\KULeuven\BREMS\MATLAB\Assignment'); %Looks into the map Assigment for the information 
Subjects = struct2table(Subjects); %Put it into a table, so you can do the following things with it
name = Subjects.name; % Takes out the column of the names 
isSub= contains(name,'A'); %Logical indexing, only the rows that contain an A are getting a 1 assignt
Sub = Subjects(isSub,1:2); %Take the first and second colum of the subjects that contain an A 
%% 
for i= 1:size(Sub,1) %For every subject in the table Sub they will run this loop
    Path = string(Sub.folder(i)); %The path to get to the folder of current the subject 
    DatumFolder = struct2table(dir(Path+filesep+string(Sub.name(i)))); %Look into the folder of the current subject
    Datum = DatumFolder.name; %Takes the row names name out of the table datumfolder
    isDatum = contains(Datum,'2018'); %Logical indexing, only the rows that contain 2018 are getting a 1 assignt
    Folder = DatumFolder(isDatum,1:2); %Take the first and second column of the datumfolder that contain 2018
    Folder2 = string(Folder.folder);%Takes the folder columns of the Folder table 
    SubjectName = Sub.name(i);%Takes the current subjects name
    Path2 = struct2table(dir(Folder2+filesep+string(Folder.name)));%Creates a path, looking into the datum folder 
    Path2 = string(Path2.folder(1)); %Takes only 1 row of the folders column to create a path
    Datastructure = Input_Data(Data, Path2, SubjectName); % uses the function made, to create a structure 
end

Answer 1

[Rik]

Your last line overwrite the struct every iteration. Using indexing will create an array:

    Datastructure(i) = Input_Data( ...

[Kaat]

If I do that it gives me an error: Error in untitled (line 20)

Datastructure(i) = Input_Data(Datastructure, Path2(i), SubjectName(i))

[Rik]

You didn't copy the entire error.

In this case the error is because in the original code you put Data and in the edit you put Datastructure, so suddenly it becomes self referential.

The exact edit required depends on what you actually want to have as a data structure after your loop.